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author | Peter Zijlstra <peterz@infradead.org> | 2019-10-09 12:44:20 +0200 |
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committer | Ingo Molnar <mingo@kernel.org> | 2019-11-27 07:44:24 +0100 |
commit | 97e6c977ccf128c3f34d6084ad53fc0021f90e03 (patch) | |
tree | e468f67349064db5ddcb040ce11d851475bd3066 /arch/x86/kernel/alternative.c | |
parent | 67c1d4a28064f9ec63df03f7798e4a334176a9cd (diff) | |
download | lwn-97e6c977ccf128c3f34d6084ad53fc0021f90e03.tar.gz lwn-97e6c977ccf128c3f34d6084ad53fc0021f90e03.zip |
x86/alternative: Remove text_poke_loc::len
Per the BUG_ON(len != insn.length) in text_poke_loc_init(), tp->len
must indeed be the same as text_opcode_size(tp->opcode). Use this to
remove this field from the structure.
Sadly, due to 8 byte alignment, this only increases the structure
padding.
Tested-by: Alexei Starovoitov <ast@kernel.org>
Tested-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20191111132457.989922744@infradead.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch/x86/kernel/alternative.c')
-rw-r--r-- | arch/x86/kernel/alternative.c | 12 |
1 files changed, 7 insertions, 5 deletions
diff --git a/arch/x86/kernel/alternative.c b/arch/x86/kernel/alternative.c index cfcfadf5cc80..6e3ee73775f6 100644 --- a/arch/x86/kernel/alternative.c +++ b/arch/x86/kernel/alternative.c @@ -938,7 +938,6 @@ static void do_sync_core(void *info) struct text_poke_loc { void *addr; - int len; s32 rel32; u8 opcode; const u8 text[POKE_MAX_OPCODE_SIZE]; @@ -965,6 +964,7 @@ int notrace poke_int3_handler(struct pt_regs *regs) { struct text_poke_loc *tp; void *ip; + int len; /* * Having observed our INT3 instruction, we now must observe @@ -1004,7 +1004,8 @@ int notrace poke_int3_handler(struct pt_regs *regs) return 0; } - ip += tp->len; + len = text_opcode_size(tp->opcode); + ip += len; switch (tp->opcode) { case INT3_INSN_OPCODE: @@ -1085,10 +1086,12 @@ static void text_poke_bp_batch(struct text_poke_loc *tp, unsigned int nr_entries * Second step: update all but the first byte of the patched range. */ for (do_sync = 0, i = 0; i < nr_entries; i++) { - if (tp[i].len - sizeof(int3) > 0) { + int len = text_opcode_size(tp[i].opcode); + + if (len - sizeof(int3) > 0) { text_poke((char *)tp[i].addr + sizeof(int3), (const char *)tp[i].text + sizeof(int3), - tp[i].len - sizeof(int3)); + len - sizeof(int3)); do_sync++; } } @@ -1141,7 +1144,6 @@ void text_poke_loc_init(struct text_poke_loc *tp, void *addr, BUG_ON(len != insn.length); tp->addr = addr; - tp->len = len; tp->opcode = insn.opcode.bytes[0]; switch (tp->opcode) { |